Three experimental HIV drugs with two entirely new mechanisms for attacking viruses promise to spur a change in how doctors treat the virus that causes AIDS, helping thousands of patients who have stopped responding to previous medicines.

The nation's schools -- under fire for unhealthy school lunches, well-stocked vending machines, and physical education cuts -- may actually do a better job than parents in keeping children fit and trim. Indiana University and Ohio State researchers found that 5- and 6-year-olds gained more weight over the summer than during the school year, casting doubt on the assumption that children are more active during the summer.

A new study in the journal Neurology is being hailed as unassailable proof that marijuana is a valuable medicine. It is a sad commentary on the state of modern medicine -- and US drug policy -- that we still need "proof" of something that medicine has known for 5,000 years, Lester Grinspoon, emeritus professor of psychiatry at Harvard Medical School, writes in an op-ed piece.